Re: tpm_tis TPM2.0 not detected on cold boot

[Jarkko Sakkinen]

On Sun, Dec 23, 2018 at 12:55:12PM +0100, Michael Niewöhner wrote:
> There is another issue but I don't know if both are related. Maybe that's just a
> timing issue...
> 
> root@debian:~# dd if=/dev/hwrng bs=1 count=1
> dd: error reading '/dev/hwrng': Operation not permitted
> 0+0 records in
> 0+0 records out
> 0 bytes copied, 0.755958 s, 0.0 kB/s
> root@debian:~# dd if=/dev/hwrng bs=1 count=1 | xxd; dd if=/dev/hwrng bs=1
> count=1 | xxd
> dd: error reading '/dev/hwrng': Operation not permitted
> 0+0 records in
> 0+0 records out
> 0 bytes copied, 0.755697 s, 0.0 kB/s
> 1+0 records in
> 1+0 records out
> 00000000: 52                                       R
> 1 byte copied, 0.0106268 s, 0.1 kB/s
> 
> 
> Michael

What does /sys/devices/virtual/misc/hw_random/rng_current show?

Did run commands as a sanity check on my laptop and seem to work.

/Jarkko